1. Field of the Invention
This invention relates to a recording head constructed with recording elements which form a plurality of dots.
2. Description of the Prior Art
As the recording means (or recording head) to be used for a facsimile device or the like, a thermal head has so far been widely adopted.
FIG. 1 of the accompanying drawing illustrates, in frontal view, a construction of a conventional recording head, in which a thermal head TH made up of a plurality of dots, i.e., heat generating elements HE which are linearly arranged in a single vertical row (in the up-and-down direction), is moved horizontally (in the left-and-right direction) to carry out the principal scanning. Further, the recording head is of such a construction that the portion of the heat generating elements HE functions to record image information on a heat-sensitive recording sheet (not shown in the drawing).
Upon completion of the horizontal scanning, the recording head returns to its original starting position, when the recording sheet is moved in the vertical direction (auxiliary scanning) so as to cause a new recording surface of the heat-sensitive recording sheet to confront to the thermal head, after which the principal scanning of the thermal head TH is resumed to perform the recording operation.
With the conventional recording head, however, there inevitably takes place a disadvantage such that a small gap (or a thin stripe) 5 would be formed between adjacent scan lines, i.e., at a portion between the upper and lower recorded portions 3 and 4 effected by the scanning operation, as shown in FIG. 2, unless a quantity or width of the recording sheet 1 fed in the direction of the arrow 2 is constant. The cause for such formation between the adjacent scan lines is irregularity in pitch or eccentricity at a drive power transmission member such as, for example, gears (not shown) for moving the recording sheet 1, or eccentricity at the roller portion, or deflection of the belt, or others. However, complete removal of these various causes is difficult. In order to eliminate this gap 5, it has so far been a practice to cause the upper and lower recorded portions formed by the scanning to slightly overlap each other. Even with such measures being taken, there still occurs from time to time such a thin, white stripe 5. In general, since such a whitened portion in the image is more conspicuous than the overlapped scan lines in the image, it was felt necessary to take steps against such whitening.